Is High-Altitude Mountaineering Russian Roulette?

Abstract

In their respective memoirs, mountaineers David Roberts and Ed Viesturs express a fundamental disagreement over the risks associated with climbing high-altitude (8000m) peaks. (Viesturs and Roberts, 2006, Roberts, 2005). For Roberts, the risk of dying on an expedition to an 8000m peak is effectively static, and so he likens it to Russian roulette. (Viesturs and Roberts, 2006, 308) Based on a 1997 study showing that “on any given expedition to an [8000m] peak. . . a climber stands a 1-in-34 chance of dying,” Roberts calculates that Viesturs had cumulatively faced a 60 percent chance of dying over his thirty expeditions on 8000m peaks.1 (Roberts, 2005, 348-49)...

This study sheds some statistical light on the Roberts-Viesturs debate and assesses whether experience is associated with lower fatality risk on 8000m peaks. Using a comprehensive dataset of high-altitude climbing expeditions in the Nepalese Himalaya, the study will estimate the conditional death risk for a member of an 8000m expedition given that climber’s number of previous expeditions. Conditional death risks are after all the core of the Roberts-Viesturs controversy. Roberts contends that the risk is constant (unconditional); Viesturs suggests that the risk of death should decrease with each ensuing climb...

Finally, I augment these basic results with three supplemental analyses. First, I offer some power calculations to justify the TTT method. Second, to control for possible confounding factors, such as year and mountain, I use a discrete-time survival analysis to model baseline hazard probabilities, which are then tested for constant or decreasing rates. Finally, to provide a useful juxtaposition, I examine the probability of ascent on 8000m peaks, asking whether previous 8000m experience increases the probability of reaching the summit.